Soriano's torrid stretch continued into Boston, where he went 3-for-4 with a three-run homer and two runs scored in the Yankees' 10-3 win over the Red Sox.
Teammate Alex Rodriguez remarked that it has looked like Soriano is "playing slow-pitch softball" over four games prior to Saturday, collecting 18 RBIs against Angels and Red Sox pitching during the span.
"It's fun. When we start winning, we start having fun," Soriano said. "This game is all about winning. When we're winning, we're having fun."
Soriano is one of six players in Major League history to tally 18 RBIs in a four-game stretch, four of whom did it for the Yankees, according to the Elias Sports Bureau.
His select group includes the Cardinals' Jim Bottomley (July 6-9, 1929), Lou Gehrig (July 29-31, 1930), Tony Lazzeri (May 21-24, 1936), Joe DiMaggio (Aug. 28-Sept. 1, 1939) and the Cubs' Sammy Sosa (Aug. 8-11, 2002).
Soriano also has at least three hits in his last four games entering play on Saturday, becoming the first Yankee to do so since Johnny Damon did it from Aug. 17-19, 2006.
"He's got a chance to do some damage," manager Joe Girardi said. "That's the guy he's been his whole career, since the day we saw him. He's got a lot of power and he has the ability to change games."
The impressive streak has also shaken up the Yankees' season leaderboard. Soriano entered play Saturday tied for fifth on the Yankees with eight homers and ranked seventh with 26 RBIs, despite having just 75 at-bats with the club after being acquired from the Cubs on July 26.
Having recently recorded his 2,000th hit, Soriano is also eyeing another milestone; he needs three homers to reach 400 for his career.
"It's nice. I don't consider myself a power hitter, but I'm close to 400," Soriano said. "I like to hit line drives. I think I've been blessed with my hands. God gave me quick hands. I've put everything together to try to get better. That's what I try to do every day."